The French did have a significant advantage with the Chassepot service rifle which out ranged everything the Prussians and there allies had but Prussian/German artillery with the Krupp steel breachloading field gun and there fusing technology negated that advantage and everything else the French had. The French were still using Napoleonic era muzzle loading artillery with unreliable fuse's. Unless they massivly nerf The Prussian batteries well below historical levels and performance the Prussian player ( with the study of history )will be able to sit outside of harms way bye a 1000 meters or more and pound the French into scrap ( as at Sedan and Metz ). Its not that the game couldn't be made its the getting somebody to play as France thats going to be the problem.

I fully agree the early battles were close run things...that changed.
Regards
Walt